Field Guide

POTS / Dysautonomia

Postural Orthostatic Tachycardia Syndrome and related autonomic dysregulation disorders where the autonomic nervous system struggles to regulate heart rate, blood pressure, temperature, and blood flow — especially with posture changes. Often overlaps with post-viral syndromes, hypermobility (hEDS), MCAS, and mitochondrial dysfunction.

A way to picture it
Your autonomic nervous system is your body's autopilot. In POTS, the autopilot glitches every time you stand up — heart racing, blood pooling, fog rolling in.
What's actually happening

In plain English

The autonomic nervous system controls heart rate, blood pressure, temperature, digestion, and blood flow — automatically, in the background. In POTS (Postural Orthostatic Tachycardia Syndrome), it fails to adapt to upright posture: heart rate rises >30 bpm within 10 minutes of standing, blood pools in the legs, and the brain briefly goes under-perfused.

Symptoms include lightheadedness, near-fainting, brain fog, exercise intolerance, heat intolerance, cold extremities, and gut symptoms. Many people are dismissed as anxious for years before diagnosis.

POTS often follows a viral illness (COVID, EBV), concussion, or surgery. It overlaps heavily with MCAS, hypermobility (hEDS), Lyme, mold, and mitochondrial dysfunction — treating those upstream drivers often improves the POTS.

Body systems affected

Where you feel it

Nervous system
Nerves, pain signals, autonomic tone
Heart & circulation
Rhythm, blood pressure, blood flow
Brain & cognition
Focus, mood, memory
Gut & digestion
Stomach, intestines, microbiome
How it develops

The step-by-step

  1. 1
    Triggering event

    Viral infection (often COVID or EBV), concussion, surgery, or prolonged bed rest disturbs the autonomic system.

  2. 2
    Autonomic dysregulation

    The nervous system fails to constrict blood vessels on standing.

  3. 3
    Compensation

    Heart rate spikes to maintain brain perfusion; catecholamines surge.

  4. 4
    Multi-system fallout

    Fatigue, fog, GI symptoms, heat intolerance, exercise crashes.

The clinical picture

Symptoms, causes & labs

Common symptoms
  • Heart racing or pounding on standing (>30 bpm rise within 10 min)
  • Lightheadedness, near-fainting, fatigue on upright activity
  • Brain fog, exercise intolerance, heat intolerance
  • Blood pooling / mottling in legs, cold extremities
  • Nausea, early satiety, bladder urgency
Possible root causes
  • Post-viral (COVID, EBV, enterovirus), post-concussion, post-surgical onset
  • Hypovolemia, deconditioning, low sodium/aldosterone
  • Overlap with MCAS, connective-tissue laxity (hEDS), Lyme, mold, autoimmunity
Labs a practitioner may consider
  • 10-minute NASA lean test or tilt-table test
  • Plasma/urine catecholamines, aldosterone, renin
  • Ferritin, B12, comprehensive thyroid, morning cortisol
  • Autoimmune / small-fiber neuropathy workup where indicated
Where you have leverage

Common lifestyle changes that help

These are the foundational shifts most often used alongside clinical care for this pattern. Start with one; layer in the next only when the first feels automatic. Discuss anything major with your practitioner.

  • 3–5 liters of fluids and 8–10g of salt daily (unless contraindicated)
  • Compression garments (waist-high 20–30 mmHg) for standing tolerance
  • Recumbent exercise first (rowing, swimming, recumbent bike), progressing slowly upright
  • Small, frequent meals — large meals shunt blood to the gut and worsen symptoms
  • Elevate the head of the bed 4–6 inches; avoid hot showers and hot environments
When to seek care

Red flags — don't wait

  • Chest pain, fainting with injury, or seizure-like episodes
  • Sudden severe headache or vision loss on standing
  • Signs of internal bleeding (black stool, severe fatigue with pallor)
Foundational levers

Supportive habits to discuss

  • Salt and fluid loading (2–3 L water, 8–10 g salt) under practitioner guidance
  • Compression garments (waist-high, 20–30 mmHg) and recumbent exercise (rowing, swimming)
  • Screen for and address MCAS, hEDS, mold, and Lyme — they commonly co-exist

Is this pattern showing up in your body?

Take our physician-designed assessment — 8 minutes, 80 questions across 25 root-cause categories.

Related categories

Medical disclaimer

This page is educational only. It is NOT medical advice, diagnosis, or treatment. Do not self-treat based on the information here. If you have symptoms, consult a licensed healthcare professional.